Fluctuating blood pressure: A warning sign for dementia and heart disease
October 16, 2023
Science Daily/University of South Australia
A new study by Australian researchers has shown that fluctuating blood pressure can increase the risk of dementia and vascular problems in older people.
Short blood pressure (BP) fluctuations within 24 hours as well as over several days or weeks are linked with impaired cognition, say University of South Australia (UniSA) researchers who led the study.
Higher systolic BP variations (the top number that measures the pressure in arteries when a heart beats) are also linked with stiffening of the arteries, associated with heart disease.
The findings have been published in the journal Cerebral Circulation -- Cognition and Behaviour.
Lead author Daria Gutteridge, a PhD candidate based in UniSA's Cognitive Ageing and Impairment Neuroscience Laboratory (CAIN), says it's well known that high blood pressure is a risk factor for dementia, but little attention is paid to fluctuating blood pressure.
"Clinical treatments focus on hypertension, while ignoring the variability of blood pressure," Gutteridge says.
"Blood pressure can fluctuate across different time frames -- short and long -- and this appears to heighten the risk of dementia and blood vessel health."
To help explore the mechanisms that link BP fluctuations with dementia, UniSA researchers recruited 70 healthy older adults aged 60-80 years, with no signs of dementia or cognitive impairment.
Their blood pressure was monitored, they completed a cognitive test, and their arterial stiffness in the brain and arteries was measured using transcranial doppler sonography and pulse wave analysis.
"We found that higher blood pressure variability within a day, as well as across days, was linked with reduced cognitive performance. We also found that higher blood pressure variations within the systolic BP were linked with higher blood vessel stiffness in the arteries.
"These results indicate that the different types of BP variability likely reflect different underlying biological mechanisms, and that systolic and diastolic blood pressure variation are both important for cognitive functioning in older adults."
The links were present in older adults without any clinically relevant cognitive impairment, meaning that BP variability could potentially serve as an early clinical marker or treatment target for cognitive impairment, the researchers say.
https://www.sciencedaily.com/releases/2023/10/231016222120.htm
Protein that could help defeat Alzheimer's and increase productive lifespan
October 5, 2023
Science Daily/Temple University Health System
Alzheimer's disease is the most common type of dementia, a disorder of progressively worsening memory and other thinking abilities. It rose up in the ranks of leading causes of death over the past several decades. It can also limit the duration of a working career, create uncertainty in the financial planning for retirement and rob patients of enjoyment and happiness in the final years. An effective treatment against this disease could give back to the patient the decision when to retire and improve quality of life in advanced age.
Now, scientists at the Alzheimer's Center at Temple at the Lewis Katz School of Medicine at Temple University are on the trail of a promising new therapeutic target -- ABCA7, a protein known to protect from Alzheimer's disease. The study, published online in the journal Cells, uncovers new information about the relationship between ABCA7, cholesterol, and inflammation in human brain cells.
The importance of ABCA7 in the development of Alzheimer's disease first emerged in genome-wide association studies, which are large investigations of the human genome that involve thousands of participants. "But genome studies only point to a protein and do not tell us anything about how it functions or how it affects a disease," said Joel Wiener, an investigator with the Alzheimer's Center at Temple and first author on the new report. "Our goal is to reveal ABCA7's functions and to use what we learn about its role in pathology to turn it into an effective therapy against Alzheimer's disease."
Previous work led by Nicholas Lyssenko, PhD, an investigator at the Alzheimer's Center at Temple and corresponding author on the new study, suggested that individuals between ages 63 and 78 who have low ABCA7 protein levels in the brain are at a greater risk of developing Alzheimer's disease. This finding corroborated the conclusions of earlier genome studies and further indicated that the protein protects the human brain.
In the new study, Dr. Lyssenko's team addressed how cholesterol metabolism and inflammation may manipulate ABCA7 levels in human brain cells and thus affect Alzheimer's disease pathogenesis. In one set of experiments, the researchers depleted cholesterol in different neural cell lines, such as microglia, astrocytes and neurons, and then treated the cells with rosuvastatin, a medication that suppresses cholesterol synthesis. To determine the effect of inflammation on ABCA7, the team carried out another set of experiments in which the same cell lines were treated with one of three major proinflammatory cytokines: IL-1β, IL-6, or TNFα. Cytokines are small molecules that can trigger inflammation following their secretion from certain types of immune cells.
The researchers found that ABCA7 levels dropped by about 40 percent in microglia cell lines and about 20 percent in an astrocyte cell line after the cells were depleted of more than half their usual amount of cholesterol. Meanwhile, no changes were observed in ABCA7 levels in a neuronal cell line following cholesterol loss. In addition, IL-1β and TNFα suppressed ABCA7 expression only in microglial cells. The third cytokine, IL-6, had no impact on ABCA7 in microglia, and none of the three cytokines induced changes in ABCA7 levels in either astrocytes or neurons.
These observations advance understanding of how ABCA7 is regulated in the brain. "Our findings suggest that cholesterol loss downregulates ABCA7 in many cells in the human brain. Previous work in mice showed that cholesterol loss upregulates ABCA7," said Mr. Wiener. "In addition, other investigators found that inflammation suppresses ABCA7 in astrocytes, and we show now that this can also happen in microglia. Overall, cholesterol depletion and inflammation may reduce ABCA7 levels in the brain and cause the onset of Alzheimer's disease."
The Temple team is taking multiple approaches to studying ABCA7, using not only human cells but also carrying out experiments in animal models and in postmortem human brain tissue. "The greatest challenge now is to figure out how to measure ABCA7 levels in the brain of living humans," Dr. Lyssenko added. "If we achieve this, we could verify whether inflammation suppresses ABCA7 in the human body. Effective testing for ABCA7 levels in the brain will also identify individuals who are at greater risk for Alzheimer's disease and spur the development of new ABCA7-based therapies."
Other researchers who contributed to the study include Sindy Desire, Viktor Garliyev, Nicholas Lyssenko III, and Domenico Praticò, Alzheimer's Center at Temple, Department of Neural Sciences, Lewis Katz School of Medicine.
The research was supported by funding from the National Institute on Aging at the National Institutes of Health (NIH) and from the Pennsylvania Department of Health, Commonwealth Universal Research Enhancement Program.
https://www.sciencedaily.com/releases/2023/10/231005173755.htm
Possible link between chronic stress and Alzheimer's disease
October 2, 2023
Science Daily/Karolinska Institutet
Researchers from Karolinska Institutet have published a study in Alzheimer's Research & Therapy that addresses possible associations between chronic stress, mild cognitive impairment and Alzheimer's disease. The study shows how people aged between 18 and 65 with a previous diagnosis of chronic stress and depression were more likely than other people to be diagnosed with mild cognitive impairment or Alzheimer's disease.
Some 160,000 people have some form of dementia in Sweden, Alzheimer's disease being the most common, a figure that is rising with our life expectancy. At the same time, many new diagnostic methods and early-intervention therapies have been developed in recent years, which foregrounds the need to identify more risk factors for the disease.
Previous studies have demonstrated a possible association between chronic stress, depression and dementia. This present study now shows that people who have been diagnosed with chronic stress or depression are more likely to be diagnosed with Alzheimer's disease.
The study shows that the risk of Alzheimer's disease was more than twice as high in patients with chronic stress and in patients with depression as it was in patients without either condition; in patients with both chronic stress and depression it was up to four times as high.
The risk of developing cognitive impairment was elevated about as much. A patient is deemed to be suffering chronic stress when he or she has been under stress with no opportunity for recuperation for at least six months.
"The risk is still very small and the causality is unknown," says the study's last author Axel C. Carlsson, docent at the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet. "That said, the finding is important in that it enables us to improve preventative efforts and understand links with the other risk factors for dementia."
The study was conducted using Region Stockholm's administrative healthcare database, which contains all healthcare contacts compensated by the region. The researchers focused on patients between the ages of 18 and 65 and between 2012 and 2013. They identified 44,447 people with a diagnosis of chronic stress and/or depression and followed them for eight years to see how many of them were later diagnosed with mild cognitive impairment or Alzheimer's disease.
A comparison with all other 1,362,548 individuals in the age bracket showed that more people with chronic stress or depression had also been diagnosed with mild cognitive impairment or Alzheimer's disease.
"It's very uncommon for people in this age group to develop dementia, so we need to identify all possible risk factors for the disease," says Dr Carlsson. "We show here that the diagnosis is more common in people who have suffered chronic stress or depression, but more studies will be required if we're to demonstrate any causality there."
The researchers will now be continuing their work and developing questionnaires and cognitive tests to aid the early identification of people at risk of dementia.
https://www.sciencedaily.com/releases/2023/10/231002124415.htm
Life satisfaction may not enhance cognitive functioning among some older adults
Feeling satisfied in life is generally thought to be a boost to physical and mental health, but a new study suggests that life satisfaction provides little benefit to older adults who also experience health or socioeconomic challenges.
September 29, 2023
Science Daily/Boston University School of Public Health
Numerous studies have shown that leading a fulfilling and satisfying life may improve cognitive function by encouraging health-protective behaviors such as physical activity and reduced stress. Many of these studies assess this relationship from a population level, rather than among individuals.
But a closer look within the general population suggests that life satisfaction may not have a positive effect on all people, according to a new study led by Boston University School of Public Health researchers.
Published in the journal SSM -- Mental Health, the study examined psychological well-being among older individuals in the United States and United Kingdom. High life satisfaction was associated with increased cognitive functioning among most individuals, but it was less beneficial for people of low socioeconomic status, in poor health, or experiencing adverse psychological conditions.
The study is the first to examine the effects of psychological well-being on cognitive functioning among older adults. It is important to note that the researchers observed no association of average cognitive effects from psychological well-being at a population level, so without this more granular analysis, the potentially adverse effects of life satisfaction would have been overlooked.
"It was impressive to observe how a relationship with no associations on population average showed underlying differences based on sociodemographic factors, physical health, and psychosocial elements," says study lead author Toshiaki Komura, a master of public health student at BUSPH.
This new insight emphasizes the importance of considering heterogeneities in public health research to understand who benefits from life satisfaction and who does not.
"Our results indicate that the health benefit of experiencing high life satisfaction may be smaller among socially marginalized groups, so further research is needed to ensure potential interventions have equitable health impacts," says study senior author Dr.Koichiro Shiba, assistant professor of epidemiology at BUSPH.
For the study, the team used a novel machine-learning method to analyze nationally representative survey data on life satisfaction and cognitive functioning among more than 15,000 adults ages 50 and older in the US and UK, for four-year periods between 2010 and 2016.
The health-promoting effect of life satisfaction in older adults was only evident among participants with higher SES, fewer pre-existing health problems, and better psychological functioning, which was about half of the survey participants.
The researchers surmise that the physical, mental, or socioeconomic challenges that low-SES individuals or adults in poorer health experience may have outweighed any possible cognitive benefits from life satisfaction. For example, life satisfaction could boost cognitive functioning by promoting physical activity, but exercise is not achievable if an individual is not in basic good health or does not have access to resources to exercise, such as residential green space or a gym.
This counterintuitive finding of the adverse effects of life satisfaction may also be explained by a concept called"response shift," which involves changing internal standards, values and the conceptualization of quality of life.
"Response shift is the adjustment of one's internal view of their quality of life when facing challenging circumstances in which their health status is severely deteriorated," Komura explains. "In such situations, their standard of quality of life may shift to maintain a favorable psychological environment."
According to this theory, individuals with disadvantaged socioeconomic, health, and psychosocial conditions might have reported life satisfaction that had been "adjusted" to their circumstances. "Our findings suggest such adjusted subjective feelings might have limited health-promoting effects on cognitive functioning," he says.
https://www.sciencedaily.com/releases/2023/09/230929131440.htm
Saturated fat may interfere with creating memories in aged brain
Study finds DHA protects brain cells from fat-related inflammation
September 27, 2023
Science Daily/Ohio State University
New research hints at a few ways fatty foods affect cells in the brain, a finding that could help explain the link between a high-fat diet and impaired memory -- especially as we age.
The Ohio State University study in cell cultures found the omega-3 fatty acid DHA may help protect the brain from an unhealthy diet's effects by curbing fat-induced inflammation at the cellular source.
Separate experiments using brain tissue from aging mice showed a high-fat diet may lead specific brain cells to overdo cell-signaling management in a way that interferes with the creation of new memories.
The same lab found in an earlier study in aging rats that a diet of highly processed ingredients led to a strong inflammatory response in the brain that was accompanied by behavioral signs of memory loss -- and that DHA supplementation prevented those problems.
"The cool thing about this paper is that for the first time, we're really starting to tease these things apart by cell type," said senior author Ruth Barrientos, an investigator in Ohio State's Institute for Behavioral Medicine Research and associate professor of psychiatry and behavioral health and neuroscience in the College of Medicine.
"Our lab and others have often looked at the whole tissue of the hippocampus to observe the brain's memory-related response to a high-fat diet. But we've been curious about which cell types are more or less affected by these saturated fatty acids, and this is our first foray into determining that."
The study was published recently in the journal Frontiers in Cellular Neuroscience.
For this work, the researchers focused on microglia, cells in the brain that promote inflammation, and hippocampal neurons, which are important for learning and memory. They used immortalized cells -- copies of cells taken from animal tissue that are modified to continuously divide and respond only to lab-based stimulation, meaning their behavior may not precisely match that of primary cells of the same type.
Researchers exposed these model microglia and neurons to palmitic acid, the most abundant saturated fatty acid in high-fat foods like lard, shortening, meat and dairy products, to observe how it affected gene activation in the cells as well as functioning of mitochondria, structures inside cells that have a primary metabolic role of generating energy.
Results showed the palmitic acid prompted gene expression changes linked to an increase in inflammation in both microglia and neurons, though microglia had a wider range of affected inflammatory genes. Pre-treatment of these cells with a dose of DHA, one of two omega-3 fatty acids in fish and other seafood and available in supplement form, had a strong protective effect against the increased inflammation in both cell types.
"Previous work has shown that DHA is protective in the brain and that palmitic acid has been detrimental to brain cells, but this is the first time we've looked at how DHA can directly protect against the effects of palmitic acid in those microglia, and we see that there is a strong protective effect," said Michael Butler, first author of the study and a research scientist in Barrientos' lab.
When it came to the mitochondria, however, DHA did not prevent the loss of function that followed exposure to palmitic acid.
"The protective effects of DHA might, in this context, be restricted to effects on gene expression related to the pro-inflammatory response as opposed to the metabolic deficits that the saturated fat also induced," Butler said.
In another set of experiments, the researchers looked at how a diet high in saturated fat influenced signaling in the brains of aged mice by observing another microglial function called synaptic pruning. Microglia monitor signal transmission among neurons and nibble away excess synaptic spines, the connection sites between axons and dendrites, to keep communication at an ideal level.
Microglia were exposed to mouse brain tissue containing both pre- and post-synaptic material from animals that had been fed either a high-fat diet or regular chow for three days.
The microglia ate the synapses from aged mice fed a high-fat diet at a faster rate than they ate synapses from mice fed a regular diet -- suggesting the high-fat diet is doing something to those synapses that gives the microglia a reason to eat them at a higher rate, Butler said.
"When we talk about the pruning, or refinement, that needs to occur, it's like Goldilocks: It needs to be optimal -- not too much and not too little," Barrientos said. "With these microglia eating away too much too soon, it outpaces the ability for these spines to regrow and create new connections, so memories don't solidify or become stable."
From here, the researchers plan to expand on findings related to synaptic pruning and mitochondria function, and to see how palmitic acid and DHA effects play out in primary brain cells from young versus aged animals.
https://www.sciencedaily.com/releases/2023/09/230927155308.htm
September 22, 2023
Science Daily/University of Tsukuba
Trigonelline is derived from coffee; researchers have found that it improves spatial learning and memory in senescence-accelerated mice. The study also suggested that this effect results from inhibiting neuroinflammation and restoring neurotransmitter levels in the brain.
The search for functional natural compounds that can improve age-related cognitive decline has recently emerged as an important research focus to promote healthy aging. Trigonelline (TG), a plant alkaloid found in coffee, as well as in fenugreek seed and radish, was anticipated to possess cognitive enhancement properties.
In this study, researchers led by the University of Tsukuba investigated the effects of TG on memory and spatial learning (acquiring, retaining, structuring, and applying information related to the surrounding physical environment) from both a cognitive and molecular biology perspective in an integrated manner using a senescence-accelerated mouse prone 8 (SAMP8) model.
Following oral administration of TG to SAMP8 mice for 30 days, the Morris water maze test indicated a significant improvement in spatial learning and memory performance compared with SAMP8 mice that did not receive TG. Next, the researchers performed whole-genome transcriptomic analysis of the hippocampus to explore the underlying molecular mechanisms. They found that signaling pathways related to nervous system development, mitochondrial function, ATP synthesis, inflammation, autophagy, and neurotransmitter release were significantly modulated in the TG group.
Furthermore, the research team found that TG suppressed neuroinflammation by negatively regulating signaling factor Traf6-mediated activation of the transcription factor NF-κB. Additionally, quantitative protein analysis confirmed that the levels of inflammatory cytokines TNF-α and IL-6 were significantly decreased and the levels of neurotransmitters dopamine, noradrenaline, and serotonin were significantly increased in the hippocampus. These findings suggest the efficacy of TG in preventing and improving age-related spatial learning memory impairment.
https://www.sciencedaily.com/releases/2023/09/230922110815.htm
A network that spreads light and the role of thalamus in our brain
September 22, 2023
Science Daily/University of Liège
New research conducted at the University of Liège, using ultra-high field 7 Tesla MRI, provides a better understanding of how light stimulates our brain and could provide new insights into how it works.
A research team at the ULiège GIGA Institute tried to understand better how light stimulates our cognition. Light acts like a cup of coffee and helps keep us awake. That's why we recommend not using too much light on our smartphones and tablets in the evening. This can disrupt our sleep. On the other hand, the same light can help us during the day. Many studies have shown that good lighting can help students in schools, hospital staff and patients, and company employees. It's the blue part of the light that's most effective for this, as we have blue light detectors in our eyes that tell our brains about the quality and quantity of light around us.
Once again, the brain regions responsible for this stimulating impact of light (also known as the 'non-visual' impact of light) are not well understood. "They are small and located in the subcortical part of the brain," explains Ilenia Paparella, doctoral student in the GIGA CRC IVI laboratory and first author of the article published in Communications Biology. The team of researchers from the GIGA-CRC-IVI was once again able to take advantage of the higher resolution of 7 Tesla MRI to show that the thalamus, a subcortical region located just below the corpus callosum (that connects our two hemispheres), plays a role in relaying non-visual light information to the parietal cortex in an area known to control attention levels. "We knew of its important role in vision, but its role in non-visual aspects was not yet certain. With this study, we have demonstrated that the thalamus stimulates the parietal regions and not the other way around, as we might have thought."
These new advances in our knowledge of the role of the thalamus will ultimately enable us to propose lighting solutions that will help cognition when we need to be fully awake and focused, or that will contribute to better sleep through relaxing light.
https://www.sciencedaily.com/releases/2023/09/230922110728.htm
Living in a disadvantaged neighborhood affects food choices, weight gain and the microstructure of the brain
September 15, 2023
Science Daily/University of California - Los Angeles Health Sciences
A new study finds poor quality of available foods, increased intake of calories from foods high in trans-fatty acids, and environments that do not foster physical activity, all prevalent in disadvantaged neighborhoods, disrupt the flexibility of information processing in the brain that is involved in reward, emotion regulation, and cognition.
You are what you eat, according to the adage. But it's not just the body that's impacted. According to research from UCLA David Geffen School of Medicine, living in a disadvantaged neighborhood can affect food choices, weight gain and even the microstructure of the brain.
The study, appearing in Communications Medicine, a Nature journal, finds poor quality of available foods, increased intake of calories from foods high in trans-fatty acids, and environments that do not foster physical activity, all prevalent in disadvantaged neighborhoods, disrupt the flexibility of information processing in the brain that is involved in reward, emotion regulation, and cognition.
Previous research showed that living in a disadvantaged neighborhood can impact brain health, but in this study, researchers did a detailed analysis of the brain's cortex to determine how living in a disadvantaged area can change specific areas of the brain that play different roles.
"We found that neighborhood disadvantage was associated with differences in the fine structure of the cortex of the brain. Some of these differences were linked to higher body mass index and correlated with high intake of the trans-fatty acids found in fried fast food," said Arpana Gupta, PhD, co-Director of the Goodman-Luskin Center and Director of the Neuroimaging Core.
"Our results suggest that regions of the brain involved in reward, emotion, and the acquisition of knowledge and understanding might be affected by aspects of neighborhood disadvantage that contribute to obesity," said Gupta, senior author. "This highlights the importance of addressing dietary quality issues in disadvantaged neighborhoods to protect brain health."
Neighborhood disadvantage is defined by a combination of such factors as low median income, low education level, crowding, and lack of complete plumbing. This study included 92 participants -- 27 men and 65 women -- from the greater Los Angeles area. Demographic and body mass index information was collected, and neighborhood disadvantage was assessed as to its area deprivation index (ADI) using University of Wisconsin School of Medicine's Public Health's Neighborhood Atlas.
Earlier studies have found that people living in disadvantaged neighborhoods are at higher risk of obesity due to the poor quality of available foods, increased intake of calories from foods high in trans-fatty acids, and environments that do not foster physical activity.
In this study, researchers focused on the relationship between ADI and neuroimaging results at four levels of the brain cortex to investigate in more refined detail the connections between neighborhood disadvantage and brain structure. Participants underwent two types of MRI scans that, when analyzed in combination, provide insights into brain structure, signaling and function.
"Different populations of cells exist in different layers of the cortex, where there are different signaling mechanisms and information-processing functions," said Lisa Kilpatrick, PhD, a researcher in the Goodman-Luskin Microbiome Center focusing on brain signatures related to brain-body dysregulation, the study's first author. "Examining the microstructure at different cortical levels provides a better understanding of alterations in cell populations, processes and communication routes that may be affected by living in a disadvantaged neighborhood."
According to the results, worse ADI ratings were associated with communication changes in brain regions that are important for social interaction. Other changes occurred in regions involved in reward, emotion regulation, and higher cognitive processes -- and these changes appeared to be affected by trans-fatty acid intake. Together, the findings suggest that factors prevalent in disadvantaged neighborhoods that encourage poor diet and unhealthy weight gain "disrupt the flexibility of information processing involved in reward, emotion regulation, and cognition."
https://www.sciencedaily.com/releases/2023/09/230915105615.htm
Large amounts of sedentary time linked with higher risk of dementia in older adults
September 12, 2023
Science Daily/University of Southern California
Researchers have used machine learning to explore the links between sedentary behavior and dementia, finding that the total time spent sedentary matters for brain aging.
Adults aged 60 and older who spend more time engaging in sedentary behaviors like sitting while watching TV or driving may be at increased risk of developing dementia, according to a new study by USC and University of Arizona researchers.
Their study showed the risk of dementia significantly increases among adults who spend over 10 hours a day engaging in sedentary behaviors like sitting -- a notable finding considering the average American is sedentary for about 9.5 hours each day.
The study, published on Tuesday, September 12 in JAMA, also revealed the way sedentary behavior is accumulated over the course of the day didn't matter as much as the total time spent sedentary each day. Whether spent in extended periods spanning several hours or spread out intermittently throughout the day, total sedentary behavior had a similar association with dementia according to study author David Raichlen.
"Many of us are familiar with the common advice to break up long periods of sitting by getting up every 30 minutes or so to stand or walk around. We wanted to see if those types of patterns are associated with dementia risk. We found that once you take into account the total time spent sedentary, the length of individual sedentary periods didn't really matter," said Raichlen, professor of biological sciences and anthropology at the USC Dornsife College of Letters, Arts and Sciences.
Researchers used data from the U.K. Biobank, a large-scale biomedical database of participants across the United Kingdom, to investigate possible links between sedentary behavior and dementia risk.
As part of a U.K. Biobank sub-study, over 100,000 adults agreed to wear accelerometers, wrist-worn devices for measuring movement, for 24 hours per day for one week. The researchers focused on a sample of approximately 50,000 adults from this sub-study over the age of 60 who did not have a diagnosis of dementia at the start of the study.
The researchers then applied a machine-learning algorithm to analyze the large dataset of accelerometer readings and classify behaviors based on different intensities of physical activity. The algorithm was able to discern between different types of activity such as sedentary behavior versus sleeping. The accelerometer data, combined with advanced computing techniques, provided researchers with an objective measure of the time spent engaging in different types of sedentary behaviors.
After an average of six years of follow-up, the researchers used inpatient hospital records and death registry data to determine dementia diagnosis. They found 414 cases positive for dementia.
Then, the team adjusted their statistical analysis for certain demographics (e.g., age, sex, education level, race/ethnicity, chronic conditions, genetics) and lifestyle characteristics (physical activity, diet, smoking and alcohol use, self-reported mental health) that could affect brain health.
Total time spent sedentary each day drives dementia risk
While high amounts of sedentary behavior were linked with increased risk of dementia, the researchers found that there were certain amounts of sedentary behavior that were not associated with dementia.
"We were surprised to find that the risk of dementia begins to rapidly increase after 10 hours spent sedentary each day, regardless of how the sedentary time was accumulated. This suggests that it is the total time spent sedentary that drove the relationship between sedentary behavior and dementia risk, but importantly lower levels of sedentary behavior, up to around 10 hours, were not associated with increased risk," said study author Gene Alexander, professor of psychology and psychiatry at the Evelyn F. McKnight Brain Institute at the University of Arizona and Arizona Alzheimer's Disease Research Center.
"This should provide some reassurance to those of us with office jobs that involve prolonged periods of sitting, as long we limit our total daily time spent sedentary," said Raichlen.
The study builds on their previous research, which used self-reported health data to investigate how certain types of sedentary behavior, like sitting and watching TV, affect dementia risk more than others.
"Our latest study is part of our larger effort to understand how sedentary behavior affects brain health from multiple perspectives. In this case, wearable accelerometers provide an objective view of how much time people dedicate to sedentary behavior that complements our past analyses," said Raichlen.
More research is needed to establish causality and whether physical activity can mitigate the risk of developing dementia, the authors said.
https://www.sciencedaily.com/releases/2023/09/230912113525.htm
Concussions early in life tied to late life cognitive decline
September 6, 2023
Science Daily/American Academy of Neurology
A study of twins shows that having a concussion early in life is tied to having lower scores on tests of thinking and memory skills decades later as well as having more rapid decline in those scores than twins who did not have a concussion, or traumatic brain injury (TBI). The study is published in the September 6, 2023, online issue of Neurology®, the medical journal of the American Academy of Neurology.
"These findings indicate that even people with traumatic brain injuries in earlier life who appear to have fully recovered from them may still be at increased risk of cognitive problems and dementia later in life," said study author Marianne Chanti-Ketterl, PhD, MSPH, of Duke University in Durham, North Carolina. "Among identical twins, who share the same genes and many of the same exposures early in life, we found that the twin who had a concussion had lower test scores and faster decline than their twin who had never had a concussion."
The study involved 8,662 men who were World War II veterans. The participants took a test of thinking skills at the start of the study when they were an average age of 67 and then again up to three more times over 12 years. Scores for the test can range from zero to 50. The average score for all participants at the beginning of the study was 32.5 points.
A total of 25% of the participants had experienced a concussion in their life.
Twins who had experienced a concussion were more likely to have lower test scores at age 70, especially if they had a concussion where they lost consciousness or were older than 24 when they had their concussion. Those twins with traumatic brain injury with loss of consciousness, more than one traumatic brain injury and who had their injuries after age 24 were more likely to have faster cognitive decline than those with no history of traumatic brain injury.
For example, a twin who experienced a traumatic brain injury after age 24 scored 0.59 points lower at age 70 than his twin with no traumatic brain injury, and his thinking skills declined faster, by 0.05 points per year.
These results took into account other factors that could affect thinking skills, such as high blood pressure, alcohol use, smoking status and education.
"Although these effect sizes are modest, the contribution of TBI on late life cognition, in addition to numerous other factors with a detrimental effect on cognition, may be enough to trigger an evaluation for cognitive impairment," Chanti-Ketterl said. "With the trend we are seeing with increased emergency room visits due to sports or recreation activity injuries, combined with the estimated half million members of the military who suffered a TBI between 2000 and 2020, the potential long-term impact of TBI cannot be overlooked. These results may help us identify people who may benefit from early interventions that may slow cognitive decline or potentially delay or prevent dementia."
A limitation of the study was that traumatic brain injuries were reported by the participants, so not all injuries may have been remembered or reported accurately.
https://www.sciencedaily.com/releases/2023/09/230906161815.htm
Researchers identify the link between memory and appetite in the human brain to explain obesity
August 30, 2023
Science Daily/University of Pennsylvania School of Medicine
Disrupted connections between memory and appetite regulating brain circuits are directly proportional to body mass index (BMI), notably in patients who suffer from disordered or overeating that can lead to obesity, such as binge eating disorder (BED), according to new research from the Perelman School of Medicine at the University of Pennsylvania. Published today in Nature, the research notes that individuals who are obese have impaired connections between the dorsolateral hippocampus (dlHPC) and the lateral hypothalamus (LH), which may impact their ability to control or regulate emotional responses when anticipating rewarding meals or treats.
"These findings underscore that some individual's brains can be fundamentally different in regions that increase the risk for obesity," senior author, Casey Halpern, MD, an associate professor of Neurosurgery and Chief of Stereotactic and Functional Neurosurgery at Penn Medicine and the Corporal Michael J. Crescenz Veterans Affairs Medical Center. "Conditions like disordered eating and obesity are a lot more complicated than simply managing self-control and eating healthier. What these individuals need is not more willpower, but the therapeutic equivalent of an electrician that can make right these connections inside their brain."
The dlHPC is located in the region of the brain that processes memory, and the LH is in the region of the brain that is responsible for keeping the body in a stable state, called homeostasis. Previous research has found an association with loss of function in the human hippocampus in individuals with obesity and related disordered eating, like BED. However, outside of imaging techniques such as magnetic resonance imaging (MRI), the role of the hippocampus has been difficult to study in humans with obesity and related eating disorders.
In this study, researchers were able to evaluate patients whose brains were already being monitored electrically in the Epilepsy Monitoring Unit. Researchers monitored brain activity as patients anticipated and then received a sweet treat (a chocolate milkshake). They found that both the dlHPC and the LH activated simultaneously when participants anticipated receiving the rewarding meal. These researchers confirmed using stimulation techniques pioneered by coauthors, Kai Miller, MD, PhD, and Dora Hermes Miller, PhD, from Mayo Clinic, that this specific zone of the hippocampus, the dlHPC, and LH exhibited extremely strong connectivity, as well.
In individuals with obesity, researchers found that the impairment of this hypothalamus-hippocampus circuit was directly proportional to their BMI. That is, in participants with a high BMI, the connection was even more disturbed.
To further validate the connection, Halpern's team used a technique called "brain clearing," to analyze brain tissue. The technique revealed melanin-concentrating hormone, a hormone known to regulate feeding behavior that is produced in the LH. They found the presence of MCH in the dlHPC, and nowhere else, confirming a link between the two regions.
"The hippocampus has never been targeted to treat obesity, or the disordered eating that can sometimes cause obesity," said Halpern. "We hope to be able to use this research to both identify which individuals who are likely to develop obesity later in life, and to develop novel therapies -- both invasive and not -- to help improve function of this critical circuit that seems to go awry in patients who are obese."
https://www.sciencedaily.com/releases/2023/08/230830131943.htm
Intermittent fasting improves Alzheimer's pathology
Mice on a time-restricted feeding schedule had better memory and less accumulation of amyloid proteins in the brain compared to controls
August 21, 2023
Science Daily/University of California - San Diego
One of the hallmarks of Alzheimer's disease is disruption to the body's circadian rhythm, the internal biological clock that regulates many of our physiological processes. Nearly 80% of people with Alzheimer's experience these issues, including difficulty sleeping and worsening cognitive function at night. However, there are no existing treatments for Alzheimer's that target this aspect of the disease.
A new study from researchers at University of California San Diego School of Medicine has shown in mice that it is possible to correct the circadian disruptions seen in Alzheimer's disease with time-restricted feeding, a type of intermittent fasting focused on limiting the daily eating window without limiting the amount of food consumed.
In the study, published August 21, 2023 in Cell Metabolism, mice that were fed on a time-restricted schedule showed improvements in memory and reduced accumulation of amyloid proteins in the brain. The authors say the findings will likely result in a human clinical trial.
"For many years, we assumed that the circadian disruptions seen in people with Alzheimer's are a result of neurodegeneration, but we're now learning it may be the other way around -- circadian disruption may be one of the main drivers of Alzheimer's pathology," said senior study author Paula Desplats, PhD, professor in the Department of Neurosciences at UC San Diego School of Medicine. "This makes circadian disruptions a promising target for new Alzheimer's treatments, and our findings provide the proof-of-concept for an easy and accessible way to correct these disruptions."
Alzheimer's disease affects more than 6 million Americans, and it is considered by many to be the biggest forthcoming health challenge in the United States. People with Alzheimer's experience a variety of disruptions to their circadian rhythms, including changes to their sleep/wake cycle, increased cognitive impairment and confusion in the evenings, and difficulty falling and staying asleep.
"Circadian disruptions in Alzheimer's are the leading cause of nursing home placement," said Desplats. "Anything we can do to help patients restore their circadian rhythm will make a huge difference in how we manage Alzheimer's in the clinic and how caregivers help patients manage the disease at home."
Boosting the circadian clock is an emerging approach to improving health outcomes, and one way to accomplish this is by controlling the daily cycle of feeding and fasting. The researchers tested this strategy in a mouse model of Alzheimer's disease, feeding the mice on a time-restricted schedule where they were only allowed to eat within a six-hour window each day. For humans, this would translate to about 14 hours of fasting each day.
Compared to control mice who were provided food at all hours, mice fed on the time-restricted schedule had better memory, were less hyperactive at night, followed a more regular sleep schedule and experienced fewer disruptions during sleep. The test mice also performed better on cognitive assessments than control mice, demonstrating that the time-restricted feeding schedule was able to help mitigate the behavioral symptoms of Alzheimer's disease.
The researchers also observed improvements in the mice on a molecular level. In mice fed on a restricted schedule, the researchers found that multiple genes associated with Alzheimer's and neuroinflammation were expressed differently. They also found that the feeding schedule helped reduce the amount of amyloid protein that accumulated in the brain. Amyloid deposits are one of the most well-known features of Alzheimer's disease.
Because the time-restricted feeding schedule was able to substantially change the course of Alzheimer's in the mice, the researchers are optimistic that the findings could be easily translatable to the clinic, especially since the new treatment approach relies on a lifestyle change rather than a drug.
"Time-restricted feeding is a strategy that people can easily and immediately integrate into their lives," said Desplats. "If we can reproduce our results in humans, this approach could be a simple way to dramatically improve the lives of people living with Alzheimer's and those who care for them."
https://www.sciencedaily.com/releases/2023/08/230821153213.htm
Caution: Living alone puts people with cognitive decline at risk
Patients forget appointments, mix up medications and have no one to contact in an emergency.
August 18, 2023
Science Daily/University of California - San Francisco
An estimated 1 in 4 older Americans with dementia or mild cognitive impairment lives alone and is at risk of practices like unsafe driving, wandering outside the home, mixing up medications and failing to attend medical appointments.
In a study publishing in JAMA Network Open on Aug. 18, 2023, researchers led by UC San Francisco concluded that the United States health system is poorly equipped to serve patients living solo with cognitive decline, a group whose numbers are predicted to swell as the population ages.
For these patients, living alone is a social determinant of health with an impact as profound as poverty, racism and low education, said first author Elena Portacolone, PhD, MBA, MPH, of the UCSF Institute for Health and Aging and the Philip R. Lee Institute for Health Policy Studies.
In this qualitative study, researchers interviewed 76 health care providers, including physicians, nurses, social workers, case workers, home care aides and others. Participants worked in memory clinics, home care services and social services and other places in California, Michigan and Texas
The providers raised concerns about patients missing medical appointments, failing to respond to follow-up phone calls from the doctor's office and forgetting why appointments were made, leaving them vulnerable to falling off the radar. "We don't necessarily have the staff to really try to reach out to them," said a physician in one interview.
Discharging a patient is like 'sending a kid out to play on freeway'
Some patients could not assist their doctor with missing information on their chart, leaving the providers uncertain about the pace of their patient's decline. Many had no names listed as emergency contacts, "not a family member, not even a friend to rely on in case of a crisis," according to a case manager.
These patients were at risk for untreated medical conditions, self-neglect, malnutrition and falls, according to the providers. A house service coordinator also noted that calls to Adult Protective Services were sometimes dismissed until a patient's situation became very serious.
One consequence of the shaky infrastructure supporting these patients was that they were not identified until they were sent to a hospital following a crisis, like a fall or reaction to medication mismanagement. Some were discharged without a support system in place. In one case, a patient was sent home with a taxi voucher, a situation that a psychiatrist likened to "sending a kid out to play on the freeway."
These findings are an indictment of our health care system, which fails to provide subsidized home care aides for all but the lowest-income patients, said Portacolone.
"In the United States, an estimated 79% of people with cognitive decline have an income that is not low enough to make them eligible for Medicaid subsidized home care aides in long-term care," she said, adding that the threshold for a person living alone in California is $20,121 per year.
While Medicare is available to adults over 65, subsidized aides are generally only provided after acute episodes, like hospitalizations, for fixed hours and for limited durations, she said.
"Most patients need to pay out-of-pocket and since cognitive impairment can last for decades, it is unsustainable for most people. Aides that are available via Medicaid are very poorly paid and usually receive limited training in caring for older adults with cognitive impairment," she added.
Subsidized home care aides plentiful in Europe, Japan, Canada
In contrast, subsidized home care aides are generally available to a significantly larger percentage of their counterparts living in parts of Europe, Japan and Canada, said Portacolone, citing a 2021 review of 13 countries, of which she was the senior author.
The study's findings illustrate substantial deficiencies in how our health system provides for people with dementia, said senior author Kenneth E. Covinsky, MD, MPH, of the UCSF Division of Geriatrics. "In an era when Medicare is going to spend millions of dollars for newly approved drugs with very marginal benefits, we need to remember that Medicare and other payers refuse to pay far less money to provide necessary supports for vulnerable people with dementia."
The researchers advocate for a system in which robust supports are made available by funding from an expanded Medicare and Medicaid. This will become increasingly critical, said Portacolone, "because effective treatments to reverse the course of cognitive impairment are unavailable, childlessness and divorce are common, and older adults are projected to live longer and often alone."
https://www.sciencedaily.com/releases/2023/08/230818135219.htm
Several vaccines associated with reduced risk of Alzheimer's disease in adults 65 and older
August 16, 2023
Science Daily/University of Texas Health Science Center at Houston
Prior vaccination against tetanus and diphtheria, with or without pertussis (Tdap/Td); herpes zoster (HZ), better known as shingles; and pneumococcus are all associated with a reduced risk for developing Alzheimer's disease, according to new research from UTHealth Houston.
A pre-press version of a study was published online recently in the Journal of Alzheimer's Disease. It was led by co-first authors Kristofer Harris, program manager in the Department of Neurology with McGovern Medical School at UTHealth Houston; Yaobin Ling, graduate research assistant with McWilliams School of Biomedical Informatics at UTHealth Houston; and Avram Bukhbinder, MD, an alumnus of the medical school. Paul E. Schulz, MD, the Rick McCord Professor in Neurology with McGovern Medical School, was senior author of the paper, which will appear in print in the Sept. 12 issue of the journal, Volume (95) Issue (2).
Alzheimer's disease affects more than 6 million people living in the U.S., with the number of affected individuals growing due to the nation's aging population.
The new findings come just over a year after Schulz's team published another study in the journal, which found that people who received at least one influenza vaccine were 40% less likely than their unvaccinated peers to develop Alzheimer's disease.
"We were wondering whether the influenza finding was specific to the flu vaccine. This data revealed that several additional adult vaccines were also associated with a reduction in the risk of Alzheimer's," said Schulz, who is the Umphrey Family Professor in Neurodegenerative Diseases and director of the Neurocognitive Disorders Center at McGovern Medical School. "We and others hypothesize that the immune system is responsible for causing brain cell dysfunction in Alzheimer's. The findings suggest to us that vaccination is having a more general effect on the immune system that is reducing the risk for developing Alzheimer's."
Researchers performed a retrospective cohort study that included patients who were free of dementia during a two-year lookback period and were at least 65 years old by the start of the eight-year follow-up period. They compared two similar groups of patients using propensity score matching, one vaccinated and another unvaccinated, with Tdap/Td, HZ, or pneumococcal vaccine. Ultimately, they calculated the relative risk and absolute risk reduction for developing Alzheimer's disease.
"This study underscores the pivotal role that large-scale, observational datasets play in biomedical research," Ling said. "It's particularly encouraging to observe consistent results across numerous large-scale health care databases."
"By leveraging modern data analysis models and the very large claims database subscribed by McWilliams School of Biomedical Informatics, we gained valuable insights into which vaccines may protect against Alzheimer's and potentially develop more effective prevention strategies," said Xiaoqian Jiang, PhD, a co-author on the study who holds the Christopher Sarofim Family Professorship in Biomedical Informatics and Bioengineering with McWilliams School of Biomedical Informatics.
https://www.sciencedaily.com/releases/2023/08/230816170628.htm
Certain sugars affect brain 'plasticity,' helping with learning, memory, recovery
August 16, 2023
Science Daily/American Chemical Society
Can you recognize someone you haven't seen in years, but forget what you had for breakfast yesterday? Our brains constantly rearrange their circuitry to remember familiar faces or learn new skills, but the molecular basis of this process isn't well understood. Today, scientists report that sulfate groups on complex sugar molecules called glycosaminoglycans (GAGs) affect "plasticity" in the brains of mice. Determining how GAGs function could help us understand how memory and learning work in humans, and provide ways to repair neural connectivity after injuries.
The researchers will present their results today at the fall meeting of the American Chemical Society (ACS).
The sugars that sweeten fruits, candies or cakes are actually just a few simple varieties of the many types of sugars that exist. When strung together, they can make a wide array of complex sugars. GAGs are formed by then attaching other chemical structures, including sulfate groups.
"If we study the chemistry of GAGs in the brain, we can learn about brain plasticity and hopefully, in the future, use this information to restore or enhance neural connections involved in memory," says Linda Hsieh-Wilson, Ph.D., the project's principal investigator presenting the research at the meeting.
"These sugars regulate numerous proteins, and their structures change during development and with disease," she explains. Hsieh-Wilson is at the California Institute of Technology.
In the brain, the most common GAG form is chondroitin sulfate, which is found throughout the extracellular matrix surrounding the brain's many cells. Chondroitin sulfate can also form structures known as "perineuronal nets," which wrap around individual neurons and stabilize the synaptic connections between them.
One way a GAG's function can be changed is through sulfation motifs, or patterns of sulfate groups tacked onto the sugar chains. Hsieh-Wilson's team is interested in how those sulfation patterns become altered, and how they might regulate biological processes such as neuroplasticity and social memory. This could also one day allow researchers to modulate these functions as a potential treatment for central nervous system injuries, neurodegenerative diseases or psychiatric disorders.
When the team deleted the Chst11 gene responsible for forming two major sulfation patterns on chondroitin sulfate in mice, defects formed in their perineuronal nets. However, the number of nets actually increased in the absence of the sulfation motifs, changing the types of synaptic connections between neurons. In addition, the mice were unable to recognize mice that they had previously been introduced to, which suggests that these patterns affect social memory.
Interestingly, these nets might be more dynamic than once thought -- they could be playing a role in both childhood and adulthood. When the researchers targeted Chst11 specifically in the brains of adult mice, they found the same effects on perineuronal nets and social memory. "That result suggests that it may be possible to manipulate these nets during adolescence or adulthood to potentially rewire or strengthen certain synaptic connections," says Hsieh-Wilson.
In other recent experiments, the team wanted to understand how GAGs and their sulfation patterns could affect axon regeneration, or the ability of neurons to rebuild themselves after injury. The researchers are now working to identify protein receptors that bind particular sulfation motifs. So far, they have found that specific motifs cause these receptors to cluster together at the cell's surface and inhibit regeneration. This process could be blocked to create tools or treatments to promote axon regeneration. Having more insight about this process could someday help repair damage caused by certain neurodegenerative diseases or strokes, Hsieh-Wilson says.
https://www.sciencedaily.com/releases/2023/08/230816114207.htm
Wildfires and farming activities may be top sources of air pollution linked to increased risk, cases of dementia
August 14, 2023
Science Daily/University of Michigan
No amount of air pollution is good for the brain, but wildfires and the emissions resulting from agriculture and farming in particular may pose especially toxic threats to cognitive health, according to new research from the University of Michigan.
Increasingly, evidence shows exposure to air pollution makes the brain susceptible to dementia. And now the findings of Boya Zhang and Sara Adar, environmental epidemiology researchers in U-M's School of Public Health, point to a strong likelihood that agriculture and wildfires, with their release of a range of harmful emissions at high concentrations, need to be more closely studied and monitored for their risks to public health, specifically dementia.
"We saw in our research that all airborne particles increased the risk of dementia but those generated by agricultural settings and wildfires seemed to be especially toxic for the brain," said Adar, associate chair of the Department of Epidemiology in the School of Public Health. She currently leads several large cohort studies on the impacts of exposures on cognitive aging and dementia.
"Our findings indicate that lowering levels of particulate matter air pollution, even in a relatively clean country like the United States, may reduce the number of people developing dementia in late life," Adar said.
Adar and Zhang's paper, "Comparison of Particulate Air Pollution From Different Emission Sources and Incident Dementia in the U.S.," appears today in the Journal of the American Medical Association's Internal Medicine.
Zhang, a research fellow who focuses on the effects of air pollution on cardiopulmonary disease and cognitive aging, said: "This work suggests that particulate matter air pollution from agriculture and wildfires might be more neurotoxic compared with other sources. However, more research is needed to confirm these effects, especially for these two sources which have received less attention in prior research."
"Given that the development of dementia could take a long time, this study mainly aimed to provide evidence for policymakers to reduce exposures to these sources of emissions," Zhang said.
The findings come as unusually poor air quality is regularly triggering alerts in the U.S. The alerts are aimed at protecting the public from the unseen, swirling mix of microscopic toxins in air pollution, specifically fine particulate matter or PM2.5. It is one of the most concerning elements of air pollution. At less than 2.5 microns in size, PM2.5 is less than the width of a human hair. Because it's so small, it can enter the brain through the nose directly or cross the blood-brain barrier in other ways. PM2.5 is also known to affect the lungs, heart, and in emerging research, the brain and cognitive function.
"These findings are quite timely given the increasing frequency of wildfire smoke in our
communities," Adar said. "Our data suggest that in addition to some of the more obvious health impacts of wildfire smoke like irritation to our throats and eyes along with breathing difficulties, high smoke days might also be taking a toll on our brains."
The record number of air quality alerts in the U.S. this year are due in large part to smoke from wildfires burning in Canada since May. The effect of wildfire is not new in the U.S., especially given the fires in the western part of the country.
Adar, a long-time environmental epidemiologist, said that wildfire smoke is becoming a more widespread stressor with many cities experiencing 30-plus days each year impacted by smoke. Given the extremely high levels of exposure to the public, wildfires are thought to contribute up to 25% of fine particulate matter exposures over a year across the U.S. and as much as 50% in some western regions of the country, Adar said.
"While individual wildfires may be short-lived, these events are becoming more frequent in our communities due to warmer temperatures, drier conditions, and longer fire seasons. As we've seen, wildfire smoke can also travel very far distances," Adar said.
Their findings are based on research into the development of dementia among nearly 30,000 adults from across the U.S. over an 18-year period. The data comes from the Health and Retirement Study, a nationally-representative collection of cohorts of older adults who have been followed since 1992. Pollution estimates in Adar and Zhang's study were based on home addresses of participants. Participants have been interviewed biennially about their cognition, overall health, and health behaviors until death or loss of contact for the survey.
They observed that higher levels of particulate matter air pollution, especially from agriculture and wildfires, were associated with greater risks of dementia. The findings could not be explained by other factors such as individual, neighborhood, socioeconomic status, occupation, or hometown or region of the country.
"With the knowledge of which sources are more toxic than others, it may be possible to design interventions for specific sources as a more effective way to decrease the burden of dementia," Zhang said.
Dementia is currently the seventh leading cause of death and one of the major causes of disability and dependency for older people, according to the World Health Organization.
The research specifically sought to test the hypothesis that a variation in emission sources could explain which are most toxic, but measuring the emissions with their distinct physical and chemical characteristics is challenging.
Past studies analyzing exposures to source specific fine particulate matter meant researchers mainly investigated relationships with the total mass of fine particulate matter in the air.
"In our study, we used a sophisticated prediction model that includes information about the chemical transformations and dispersion of pollution from different sources to estimate the levels of source-specific particulate matter air pollution at participants' residential addresses," Zhang said. "This approach is beneficial because it not only accounts for pollution directly emitted by a source but also pollution generated through reactions with other chemicals in the air."
Since the average level of exposure to PM2.5 for the people studied was less than the National Ambient Air Quality Standard, this is not just an issue of extreme pollution events, the researchers say, though it's clear that the air quality from wildfire events is worsening. This research suggests that it's not just sending people with respiratory ailments to the hospitals but there may also be longer lasting effects to the body. With the changing climate, it's likely that these threats to health will increase.
The study was funded by the National Institute of Environmental Health Sciences and the National Institute of Aging.
https://www.sciencedaily.com/releases/2023/08/230814121753.htm
People's everyday pleasures may improve cognitive arousal and performance
August 8, 2023
Science Daily/NYU Tandon School of Engineering
Developed over the past six years, MINDWATCH is an algorithm that analyzes a person's brain activity from data collected via any wearable device that can monitor electrodermal activity (EDA). This activity reflects changes in electrical conductance triggered by emotional stress, linked to sweat responses.
Listening to music and drinking coffee are the sorts of everyday pleasures that can impact a person's brain activity in ways that improve cognitive performance, including in tasks requiring concentration and memory.
That's a finding of a new NYU Tandon School of Engineering study involving MINDWATCH, a groundbreaking brain-monitoring technology.
Developed over the past six years by NYU Tandon's Biomedical Engineering Associate Professor Rose Faghih, MINDWATCH is an algorithm that analyzes a person's brain activity from data collected via any wearable device that can monitor electrodermal activity (EDA). This activity reflects changes in electrical conductance triggered by emotional stress, linked to sweat responses.
In this recent MINDWATCH study, published in Nature Scientific Reports, subjects wearing skin-monitoring wristbands and brain monitoring headbands completed cognitive tests while listening to music, drinking coffee and sniffing perfumes reflecting their individual preferences. They also completed those tests without any of those stimulants.
The MINDWATCH algorithm revealed that music and coffee measurably altered subjects' brain arousal, essentially putting them in a physiological "state of mind" that could modulate their performance in the working memory tasks they were performing.
Specifically, MINDWATCH determined the stimulants triggered increased "beta band" brain wave activity, a state associated with peak cognitive performance. Perfume had a modest positive effect as well, suggesting the need for further study.
"The pandemic has impacted the mental well-being of many people across the globe and now more than ever, there is a need to seamlessly monitor the negative impact of everyday stressors on one's cognitive function," said Faghih. "Right now MINDWATCH is still under development, but our eventual goal is that it will contribute to technology that could allow any person to monitor his or her own brain cognitive arousal in real time, detecting moments of acute stress or cognitive disengagement, for example. At those times, MINDWATCH could 'nudge' a person towards simple and safe interventions -- perhaps listening to music -- so they could get themselves into a brain state in which they feel better and perform job or school tasks more successfully."
The specific cognitive test used in this study -- a working memory task, called the n-back test -- involves presenting a sequence of stimuli (in this case, images or sounds) one by one and asking the subject to indicate whether the current stimulus matches the one presented "n" items back in the sequence. This study employed a 1-back test -- the participant responded "yes" when the current stimulus is the same as the one presented one item back -- and a more challenging 3-back test, asking the same for three items back.
Researchers tested three types of music -- energetic and relaxing music familiar to the subject, as well as novel AI-generated music that reflected the subject's tastes. Consistent with prior MINDWATCH research, familiar energetic music delivered bigger performance gains -- as measured by reaction times and correct answers -- than relaxing music. While AI-generated music produced the biggest gains among all three, further research is needed to confirm those results.
Drinking coffee led to notable but less-pronounced performance gains than music, and perfume had the most modest gains.
Performance gains under all stimulations tended to be higher on the 3-back tests, suggesting interventions may have the most profound effect when "cognitive load" is higher.
Ongoing experimentation by the MINDWATCH team will confirm the efficacy of the technology's ability to monitor brain activity consistently, and the general success of various interventions in modulating that brain activity. Determining a category of generally successful interventions does not mean that any individual person will find it works for them.
The research was performed as a part of Faghih's National Science Foundation CAREER award on the Multimodal Intelligent Noninvasive brain state Decoder for Wearable AdapTive Closed-loop arcHitectures (MINDWATCH) project. The study's diverse dataset is available to researchers, allowing additional research on the use of the safe interventions in this study to modulate brain cognitive states.
https://www.sciencedaily.com/releases/2023/08/230808151255.htm